Neurocognitive performance in patients with depression compared to healthy controls: Association of clinical variables and remission state.

Cognitive impairment in Major Depressive Disorder (MDD) has been postulated to persist into remission. However, inconsistent definitions of clinical remission, patterns and influencing factors, isolated cognitive tasks, and the lack of appropriately matched controls (HCs) present significant limitations of previous studies. Furthermore, studies investigating cognition in partially remitted patients are particularly scarce. This study compares the cognition of MDD patients (N = 65) and HCs (N = 65), matched by one-to-one recruitment strategy for age, sex, and education (ages 19-60). The neuropsychological (NPS) performance was measured via an extensive NPS-test battery and analysed retrospectively, accounting for demographic and clinical variables. Full remission was defined as HAMD cut off ≤7, partial remission as HAMD 8-18. The findings show entire MDD group and partially remitted MDD with significantly poorer NPS performance compared to HCs, while remitted MDD patients did not differ significantly from HCs. This underscores how critical a clear definition of remission is to compare studies on MDD. The clinical variable 'number of hospitalizations' had a significant effect on cognition, whereas current symptom severity did not correlate with performance on any cognitive domain. Higher number of hospitalizations may be associated with higher burden of illness and greater neurobiological "scar effects".